A wheat field in Suffolk, England. Green groups want protections for wildlife to be strongly linked to new farming subsidies as the UK leaves the EU.
Photograph: Graham Turner for the Guardian

New subsidies paid to farmers under a post-Brexit government must be linked closely to environmental responsibilities, a large group of political and civil society organisations has urged.

Protection for birds, wildlife, waterways and other natural goods should come top of the list when any new payments are considered, wrote 84 food, farming and conservation specialists in a letter to Oliver Letwin and Theresa May on Thursday.

It is too early to say what May’s plans are for farming, but the organisations - including the Campaign for the Protection of Rural England, Greenpeace, Friends of the Earth, the Wildlife Trust, War on Want and several parliamentary groups - want to persuade ministers ahead of negotiations that if farmers are to receive payments from the UK taxpayer under a new government, they should be strongly linked to the conservation of nature.

“Food, farming and fishing policies, and the sectors’ compliance with strong environmental protections, designed explicitly to achieve public good, must be the bedrock principle for any post-EU referendum negotiations,” wrote the leaders. “Public spending on subsidies, research or other support must be directly linked to public goods.”

As well as subsidies, any new trade agreement negotiations must include environmental protections as a priority, the signatories wrote. Higher animal welfare standards would be one important protection, as currently minimum standards are set under the EU, though the UK government has frequently imposed more stringent rules on British farmers, under public pressure.

“We are seriously concerned that such considerations may be over-run by a drive for new trade deals at any cost, and pressures to de-regulate,” they said. Countries such as the US and China, seen as key trading partners in post-Brexit negotiations, have much lower animal welfare standards than in the UK.

Subsidies are still crucial to small farmers, as they make the difference between profit and loss for thousands.

A return to production-based subsidies, phased out a decade ago, but which some small farmers favour, could mean that land currently given over to nature would be intensively cultivated, green campaigners fear. This could be mitigated if farmers in receipt of subsidy were given strong environmental responsibilities in return.

Other measures that should be considered, according to the letter, include requirements for public procurement of food to come from sustainable sources in the UK, the letter said, and current initiatives on issues such as childhood obesity should not be abandoned under commercial pressure. They called for civil servants with food and farming expertise to be included in the government’s new department focused on Brexit, and for consultation with scientists and civil society organisations.

Organisations signing the letter included: Action on Sugar, the London Food Board, the Soil Association, the Fairtrade Foundation, Forum for the Future, Environmentalists for Europe, Unison and Unite the Union , Compassion in World Farming and the World Cancer Research Fund.

In parliament, in a hearing of the select committee on energy and climate change, senior government officials told MPs that the UK’s current targets on renewable heat and transport would still stand, while the UK is a member of the EU. “We still see these as binding,” said Lord Bourne of Aberystwyth.

Andrew Jones, parliamentary under secretary of state at the Department for Transport, said “we think we are going to meet it”, despite National Grid saying last week that the target is unlikely to be met until 2022.